Enable generation of instruction buffer on precompilation

runtime/BUILD.gn

Index: runtime/BUILD.gn
diff --git a/runtime/BUILD.gn b/runtime/BUILD.gn
index cbc064398d7b5fa50dbc9cb7073622e376fa502e..b17dc80ab19c377726a7af84ab44408246cf3f4c 100644
--- a/runtime/BUILD.gn
+++ b/runtime/BUILD.gn
@@ -21,6 +21,12 @@ config("dart_public_config") {
 
 config("dart_config") {
   defines = []
+  if (!is_ios || !is_android) {

[rmacnak, 2015/10/21 23:06:18]

Won't this also cause desktop Linux builds to use the simulator?

[Chinmay, 2015/10/22 00:13:16]

Good point. I have switched this to a target_os check

+    # For precompilation, we need to set the target architecture when we
+    # compile the snapshotter on the host. If no instruction buffer is created
+    # on the host, this argument is of no consequence.
+    defines += ["TARGET_ARCH_ARM64"]
+  }
   if (dart_debug) {
     defines += ["DEBUG"]
   } else {